a Radiant question

[precaud]

Two pipes - one stainless steel, one painted black. Both have an identical stream of hot air/gasses flowing through.
The black one emits significant radiant heat. The stainless one doesn't.
What happens to the heat/energy that the stainless pipe doesn't radiate? Is it lost?

 

[MountainStoveGuy]

i would guess that stainless has more insulationg properties then the rolled steel. The heat is contained in the pipe and going up the flue! improving draft on the way. Im taking chemistry this semester, maybe i will find out.

 

[precaud]

Interesting, MSG... I'll poke around later and see if conductivity is different for these materials. Thanks.

 

[MountainStoveGuy]

Another place you see this is in the grill industry. Stainless grill not only look pretty, they also increase the overall efficiency of the grill. I will use Ducane for example, back in the day before weber bought them and whored them to china, they made a alluminum head grill (1205) and a stainless one (7100). They were roughly the same BTU's. Up in altitude the 1205 series never got hot, people always complained. We bought a 7100 and brought it to a customer to use for a few months, the difference was incredible. The stainless grill got hotter, faster and maintained temp. Now to be fair the 1205 was aluminum, which we know coducts heat way better then stainless. If you shop around, you will notice that most of the high end stainless grills have less btu imputs then there cast iron, steel, or aluminum counter parts.

 

[Roospike]

Another place you see this is in the grill industry. Stainless grill not only look pretty, they also increase the overall efficiency of the grill. I will use Ducane for example, back in the day before weber bought them and whored them to china, they made a alluminum head grill (1205) and a stainless one (7100). They were roughly the same BTU's. Up in altitude the 1205 series never got hot, people always complained. We bought a 7100 and brought it to a customer to use for a few months, the difference was incredible. The stainless grill got hotter, faster and maintained temp. Now to be fair the 1205 was aluminum, which we know coducts heat way better then stainless. If you shop around, you will notice that most of the high end stainless grills have less btu imputs then there cast iron, steel, or aluminum counter parts.

MountainStoveGuy hit the nail on the head . "Now to be fair the 1205 was aluminum, which we know coducts heat way better then stainless."

 

[MountainStoveGuy]

My theroy is a long way from being scientific, it would be intresting to look at how it calculates out. To get something remotly accurate, we need to know the exact type of stainless, and the steel its being compared to. Then bust out the chemistry book and do some calculations.

 

[elkimmeg]

I think one has to look at the reflective values Most stailless steel id shiny polished smooth surfaces more so than mild steel pipe One also has to look at the thicknessed the thicker mild steel has more mass to absorbe and hold heat. If both gages are the same forget that last statement then there is molecular structure molicules of ss are thghter than the mild steel so more room fo store heat more ability for absorption

 

[precaud]

OK, from what I've found, carbon steel is 4X more conductive than stainless (and aluminum is 12X.) So clearly, it doesn't "absorb" as much heat as a normal steel pipe, i.e. it runs cooler.
But the question remains: what happens to the heat that it doesn't radiate? Seems it is either stored and released via convection, or it goes up the flue... what else is there?

 

[elkimmeg]

Still trying to justify using connector pipe for liner purposes? Thats why ss is used the heat stays in the chimney to promote positive draft . Where heat is lost 4 times faster out of the black connector pipe cooling down the insides weaking its draft abilities as it cools it condensated and induces cersote build up also the surface being more pourus also adds to the build up issue
Then SS is corrosive resistant to H2/S04 Where mild steel is not. Rust forms making the surface even less friction resistant.
which exccelerates the decaying process and cresote build up. If you are going to just do it why debate it? If you and steve just want to dismiss it as excessive code enforcement, there is nothing more I can say to already closed ears and minds.

This was fished out of a home used as a liner. The older gent installed it or had it installed 5 to 7 years back. Unfortunately he did not have a tight damper seal. The medics were able to save his life from Co poisoning. He suffered brain damage and is residing in a rest home. He will never return to his home again. This happened in my town. I knew the guy guite well. You bet I never knew of this install or situation. it was done without a permit. The fire dept. called me in to confirm improper galzanized pipe was used as a liner.

This was the only whole section left the rest disingrated. And galzanized is suposed to be much less corrosive restiant than mild steel. Had this guy used a proper ss liner,, I could visit him at his home today. We were fellow classic car hobbist. He was a terrific mechanic

 

[precaud]

Still trying to justify using connector pipe for liner purposes?

Can the cynicism, elk. Inquiring minds ask questions.

 

[elkimmeg]

I try to answer the questions honestly and fairly. Which I think I did. Ask away

What is the price difference between 22 gage connector pipe and an approved ss liner? we all know ss smooth liner is much more expensive but also better

 

[precaud]

You missed the point. The purpose of this thread is not to justify anything. It's to understand what happens to the heat that isn't radiated. What you posted has to do with a different thread, not this one.

 

[Eric Johnson]

If it's not radiating through the liner, then obviously it goes up the stack. That's not really "losing" it, since it provides a valuable service on its way up. While you do want exposed connector pipe to radiate heat, that's the last thing you want a chimney to do.

 

[elkimmeg]

The heat is dissipated in your existing masonry chimney some willl rise outside the liner and out the cap
Some of the heat will be absorbed by the masonry chimney and finally lost to the attmosphere in the out side section or exposed section of the chimney. If an interior masonry chimney this would not be all that bad, to heat up the masonry and then have some radiate back into the living space.